1. Technical Field
The present invention relates to a hydraulic power steering assembly for steering a vehicle and, particularly, to a damping ring assembly for attenuating noise caused by vibrations in a hydraulic power steering assembly.
2. Description of the Prior Art
Hydraulic power steering assemblies for steering a vehicle are known. One common type of hydraulic power steering assembly is a power assisted rack and pinion steering assembly having a housing which supports a rack for longitudinal movement to steer the vehicle. The housing contains a hydraulic control valve. The control valve responds to rotation of an input shaft connected with the vehicle steering wheel to regulate the flow of hydraulic fluid to a hydraulic cylinder containing a piston that moves the rack. The control valve includes a valve core and a valve sleeve which are supported for rotation relative to each other and which have surfaces which define hydraulic fluid flow paths through the valve assembly.
The pressurized flows of hydraulic fluid in the control valve can cause vibrations in the valve assembly in the nature of undesired oscillation between the valve core and the valve sleeve. The vibrations in the control valve can cause noises that are audible to an occupant of the vehicle. It is desirable to minimize undesired oscillation between the valve core and the valve sleeve, so as to minimize audible noise emanating from the steering gear.